scholarly journals Optical Heterodyne Measurement of Terahertz Wave

2021 ◽  
Author(s):  
Shin’ichiro Hayashi ◽  
Norihiko Sekine
Keyword(s):  
Wavelength Conversion ◽  
Nonlinear Crystal ◽  
Terahertz Wave ◽  
Nonlinear Frequency ◽  
Optical Heterodyne ◽  
Research Fields ◽  
Terahertz Region ◽  
Pyroelectric Detectors ◽  
New Research ◽  
Non Destructive

One of the most notable frequency regions in terms of research currently lies in the ‘frequency gap’ region between microwaves and infrared: terahertz wave. Although new methods for generating and detecting terahertz wave have been developed, few detectors operating at room temperature are able to capture low-energy terahertz beams. Here we introduce the optical heterodyne measurement (nonlinear frequency up-conversion detection) of terahertz wave using parametric wavelength conversion in a nonlinear crystal; this has better sensitivity than many commonly used thermal detectors such as pyroelectric detectors. Additionally, optical heterodyne techniques allow the beams of terahertz wave to be visualized and their frequency and intensity determined directly as visible light. These are very promising for extending applied researches into the terahertz region, and we expect that these will open new research fields such as wireless information communications or non-destructive inspection in the terahertz region.

Corruption and anti-corruption local discourses and international practices in post-socialist Romania

Human Affairs ◽  
2013 ◽  
Vol 23 (2) ◽  
Author(s):  
Filippo Zerilli
Keyword(s):  
Cultural History ◽  
Research Literature ◽  
The European Union ◽  
The Past ◽  
Research Fields ◽  
Nation States ◽  
National Heritage ◽  
New Research ◽  
Local Discourses ◽  
The Cold War

AbstractIn the past two decades academic and research literature on “corruption” has flourished. During the same period organizations and initiatives fighting against corruption have also significantly expanded, turning “anti-corruption” into a new research subject. However, despite a few exceptions there is a division of labor between scholars who study corruption itself and those who study the global anti-corruption industry. Juxtaposing corruption’s local discourses and anti-corruption international practices, this article is an attempt to bring together these two intertwined research dimensions and explore how an ethnographic approach might contribute to framing them together. Firstly, it describes how corruption in Romania is often conceptualized and explained in terms of national heritage, something related to old and recent cultural history, including traditional folklore. Secondly, it explores how anti-corruption works in practice, focusing on international legal cooperation projects monitoring the progress and shortcomings both prior to and post Romania’s accession to the European Union. Finally, revealing the articulations of these two apparently unrelated research fields, the article argues that corruption’s local explanations and the circular logic of auditing observed within the anti-corruption industry share a common developmental ideology mirroring the crypto-colonialist structure of power relations and dependency among European nation-states emerging out of the Cold War.

Exploring climate finance for tourism adaptation development: an overview

2016 ◽  
Vol 8 (5) ◽  
pp. 593-605 ◽  
Author(s):  
Daniele Vieira do Nascimento
Keyword(s):  
Climate Change ◽  
Literature Review ◽  
English Language ◽  
Small Island ◽  
Future Research ◽  
Climate Finance ◽  
Content Type ◽  
Main Research ◽  
Research Fields ◽  
New Research

Purpose The purpose of this paper is to provide an overview of the links between climate finance and tourism adaptation development. Besides increasing adaptation and mitigation efforts to limit greenhouse gas emissions, climate change remains a major challenge in the twenty-first century and beyond especially for tourism which is highly climate sensitive. Hence, it is necessary for tourism to adapt to survive. The aim of the study is to provide a systematic overview of the topic to offer a foundation for better understanding different ways of integrating climate finance initiatives with tourism. Design/methodology/approach The research focused on the top-ranked, peer reviewed journals of each of the two selected research fields. To address this topic, an in-depth systematic literature review in the fields of climate change finance and tourism adaptation development was conducted. Furthermore, because it is a relatively new research topic, conference proceedings were also explored. To guarantee wide coverage of the literature, a query of the following scholarly databases was considered: Elsevier, ScienceDirect and Web of Science. Findings Based on the analyses of the literature available on the topic, the paper highlights the main research trends and conclusions. It is argued that there is imbalance of knowledge on climate change finance as it relates to tourism. To date, there have been relatively few published articles on this topic in the context of tourism. Based on the findings, promising areas for future research were identified, and in particular for small island communities and recommendations for future research are outlined. Research limitations/implications The paper is limited by the scope of the literature review accessed by the researcher. The results of this review may vary according to the databases used. Originality/value Currently, there is no extensive review of articles on climate finance and tourism adaptation. This paper aims at reviewing climate finance studies published in English language to explore knowledge gaps in tourism adaptation. Sets of themes being advanced are also highlighted. Recommendations for future research are provided.

Analysis of Aluminium Beam-to-Column Joints by the Component Method: Existing Studies and Research Needs

2016 ◽  
Vol 710 ◽  
pp. 409-414 ◽  
Author(s):  
Gianfranco De Matteis ◽  
Giuseppe Brando
Keyword(s):  
Current Knowledge ◽  
Component Method ◽  
The Past ◽  
Research Fields ◽  
Numerical Studies ◽  
Current State ◽  
Moment Resisting ◽  
New Research ◽  
Steel Joints

This paper aims at providing an overview on the current state of the art and on possible future developments concerning the component method implementation for the classification of beam-to-column joints belonging to aluminum moment resisting frames.After a brief discussion on the component method theoretical bases, developed in the past to give a feasible calculation procedure for steel joints, recent experimental and numerical studies, carried out for investigating some aluminum components, are presented and discussed. In particular strengths and weaknesses of the current knowledge are put into evidence, also in light of the peculiarities that make aluminum alloys different from steel. The launch of new research fields, aimed at pursuing an update of the current codes dealing with aluminum structures, is therefore proposed.

scholarly journals Effective Generation of Milliwatt-Level Sub-Terahertz Wave for Nonlinear Response Measurement of Two-Dimensional Material by Optical Heterodyne Technique

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Shuqing Chen ◽  
Zhiqiang Xie ◽  
Junmin Liu ◽  
Yanliang He ◽  
Yao Cai ◽  
...  
Keyword(s):  
Nonlinear Response ◽  
Modulation Depth ◽  
Terahertz Wave ◽  
Saturable Absorption ◽  
Optical Heterodyne ◽  
Two Dimensional ◽  
Response Measurement ◽  
Microwave Source ◽  
Terahertz Band ◽  
Heterodyne Technique

By using optical heterodyne technique, we demonstrated the stable emission of sub-terahertz wave with the frequency ranging from 88 GHz to 101 GHz, which can operate as microwave source for nonlinear response measurement system. Mutual frequency beating of two well-separated sideband signals at a 0.1 THz photo-detector (PD) allows for the generation of sub-terahertz signal. Based on this approach, we have achieved the radiation of 0.1 THz wave with power up to 4 mW. By transmittance measurement, two-dimensional nanomaterial topological insulator (TI: Bi2Te3) shows saturable absorption behaviors with normalized modulation depth of 47% at 0.1 THz. Our results show that optical heterodyne technique could be developed as an effective microwave source generation for nonlinear measurement at sub-terahertz, even terahertz band.

Physics of Gauge Fields in Quantum Nanosciences

SPIN ◽  
2020 ◽  
Vol 10 (03) ◽  
pp. 2050018
Author(s):  
Seng Ghee Tan ◽  
Mansoor B. A. Jalil ◽  
Ching-Ray Chang ◽  
Shuichi Murakami
Keyword(s):  
Future Development ◽  
Momentum Space ◽  
Condensed Matter ◽  
Equations Of Motion ◽  
Frame Of Reference ◽  
Gauge Fields ◽  
The Past ◽  
Research Fields ◽  
New Research ◽  
The Impact

We review the formulation of gauge fields in terms of the frame of reference as well as the space in which the frame is defined. We highlighted some recent applications of gauge physics in the momentum space — in the modern fields of the spin Hall effect, the magnon Hall, the optical Magnus and the graphene valley Hall. General procedures of gauge transformation which lead to the construction of the gauge curvature and the equations of motion (EOM) are outlined. Central to this review is our intention to illustrate the impact of gauge physics on the past and future development of many new research fields emerging out of condensed matter physics, particularly in quantum nanosciences and nanoelectronics.

Emotional Expression System Based on Expression Intensity Recognition and Affective Model

2013 ◽  
Vol 461 ◽  
pp. 618-622
Author(s):  
Chuan Wan ◽  
Yan Tao Tian
Keyword(s):  
Facial Expressions ◽  
Affective Computing ◽  
Expression System ◽  
Human Head ◽  
Virtual Human ◽  
Generation Model ◽  
Recognition Of Facial Expressions ◽  
Research Fields ◽  
Emotion Generation ◽  
New Research

Affective computing is an indispensable aspect in harmonious human-computer interaction and artificial intelligence. Making computers have the ability of generating emotions is a challenging task of affective computing. Affective Computing and Artificial Psychology are new research fields that involve computer and emotions, they have the same key research aspect, affective modeling. The paper introduces the basic affective elements, and the representation of affections in a computer. And we will describe an emotion generation model for a multimodal virtual human. The relationship among the emotion, mood and personality are discussed, and the PAD emotion space is used to define the emotion and the mood. We obtain the strength information of each expression component through fuzzy recognition of facial expressions based on Ekman six expression classifications, and take this information as a signal motivating emotion under the intensity-based affective model. Finally, a 3D virtual Human head with facial expressions is designed to show the emotion generation outputs. Experimental results demonstrate that the emotion generation intensity-based model works effectively and meets the basic principle of human emotion generation.

Terahertz-wave parametric wavelength conversion at room temperature

2017 ◽  
Author(s):  
Shin’ichiro Hayashi ◽  
Kouji Nawata ◽  
Kodo Kawase ◽  
Hiroaki Minamide
Keyword(s):  
Room Temperature ◽  
Wavelength Conversion ◽  
Terahertz Wave

The Present Situation and Developing Trends of Hot Closed-Die Forging

2015 ◽  
Vol 1094 ◽  
pp. 365-368
Author(s):  
Qi Liu ◽  
Xu Guang ◽  
Shi Xuan Sun
Keyword(s):  
Machine Building ◽  
Production Costs ◽  
Research Issues ◽  
Slowing Down ◽  
Research Fields ◽  
Precision Forging ◽  
Die Forging ◽  
Closed Die Forging ◽  
New Ideas ◽  
New Research

Due to its advantages including high quality of the forging parts and low production costs,hot closed-die forging (HCDF) play an essential role in the machine building industry. However, in recent decades, the pace of its development is gradually slowing down. In the hope of drawing up some new ideas about future development of the HCDF, this paper presents a brief overview of it. This study roughly prospects several potential research issues of the HCDF. Some new research fields such as precision forging, combined forging and numerical simulation have been shown. Challenges and possible response to them have been discussed.

Sign in / Sign up

Export Citation Format

Share Document